Progressive people and politicians in the UK should end the “idiocy” of wishing for a second referendum on Brexit and instead turn to what can be salvaged from leaving the EU, according to Yanis Varoufakis, the former Greek finance minister.

Even though the UK is likely to leave the EU with a bad deal, it can still work with other governments on the continent to end austerity and raise living standards, he said.

“It’s time to turn the page, to accept that it’s happening,” Varoufakis told Big Issue North. “It’s happening in a disastrous way but Theresa May is going to be allowed to see it through because the Cabinet does not want to fell her until she delivers something that they can then shoot her over.

“So there won’t be a general election, there won’t be a referendum, there won’t be a parliamentary debate over it.”

“In but against” EU

Varoufakis negotiated the most recent EU bailout for Greece but resigned from the government because he believed his one-time ally and prime minister, Alexis Tsipras, climbed down in the face of demands by the troika of financial institutions that the government impose even more austerity on its people.

He is a co-founder of the Democracy in Europe Movement 2025, or DiEM25, a progressive movement seeking to reform the EU by being “in but against”, and has recently launched a new political party in Greece that will stand in elections promising to end the country’s “debt bondage”.

As one example of a policy DiEM25 would support, Varoufakis suggested co-operation between European state investment banks on a massive green new deal that would boost renewable energy supplies and bring many new well paid jobs.

He said investment in Europe was at a 60-year low even though rich individuals and corporations were sitting on more wealth than ever before.

“Lift all boats”

“How could we emulate a democratic European union when there is none?” he said. “Jeremy Corbyn is talking about creating an investment bank along the lines of the Post Office savings bank – which used to be an investment bank. Let’s say he does. It won’t be enough because there won’t be enough investment capital in it.

“But we have the European Investment Bank in Europe. There is a German one, there is a French one, there is a Swedish one.

“Imagine if you had a press conference – no need for treaties, European Union institutions, anything like that – just a press conference. The heads of all these investment banks announce that they will collaborate and borrow from the private sector – issue bonds – £600-£700 billion every year for the whole of Europe. Now that’s a fantastic sum to invest across Europe. It would lift all boats.”

He said a co-ordinated promise by the heads of Europe’s central banks, including the Bank of England, to buy those bonds if others would not would support their value, giving private investors the confidence to buy them.

“Suddenly you have a huge green new deal for the whole of Europe,” said Varoufakis, speaking before a speech to Sheffield’s Festival of Debate. “So who gives a damn if Britain is in the EU?

“These are the things that we at DiEM25 are talking about. These are the things that can bring people together. What progressive in their right mind could ever object to this, whether they are Remainers, Leavers, half way house, whatever?”

Varoufakis also warned that those who believe the UK can stay in the EU single market but still end free movement of people were mistaken. “That’s nonsense,” he said. “I gave a speech to Labour MPs in the House of Commons a few weeks ago advocating a Norway-plus solution, which would maintain free movement of people.

“I am a strong believer in freedom of movement, not just in Europe but everywhere. It’s just a joke to be saying to the rest of the world that we are going to be stopping people at the border. It’s preposterous.”

But it is not only Brexiters who are proposing putting up barriers. Among EU members, Hungary’s leader Viktor Orban has just won another term by amplifying his anti-immigrant stance, while an government assault on the freedom of the judiciary in Poland has brought fears that the EU’s liberal values are under threat, particularly in former Soviet bloc countries.

The European Commission has threatened disciplinary action against Poland but its scope to act is limited. How would DiEM25 approach the problem?

“Iron-clad, manic might”

“In our manifesto, which was written well before Orban became such a menace we were very clear – we believe in an open Europe, we believe in a social Europe and we believe in a humanist Europe, so anyone who manages to speak to the fears of the populace, securing a mandate on the basis that we hate foreigners and we are going to keep them out at our borders while at the same time demanding we are in the European Union, should be confronted,” Varoufakis replied.

He said the contrast was “astonishing” between how the EU, “in all its iron-clad, manic might”, came down on the Greek government for resisting its demand to cut pensions for the poorest and its treatment of Hungary and Poland.

“Look what’s happening in Spain too with the Catalonians. Whether or not you are in favour of independence – the fact is that there are politicians in jail in Europe and Brussels is whistling in the wind and pretending this is not anything to do with the European Union.”

As well as support for migrants and refugees and a revitalisation of the European economy, DiEM25 is calling for transparency in the EU decision making process, where the roles and responsibilities of the main institutions remains unclear not only to millions of citizens but those who deal with them directly – like Varoufakis.

He said the outcome of the Greek negotiations he was involved with would have been “very different” if, for example, EU meetings were held in public.

“The way they divided and ruled over us was through opacity. I was saying one thing in the Eurogroup and they were reporting another. So imagine if these Eurogroup meetings were live-streamed – the whole thing would have collapsed…

“If there was transparency they would not have even been able to convince their own people. This character assassination plot – it was a plot – to portray our government as unreasonable rule breakers would simply have vanished.”

The political maze was laid out in Varoufakis’s 2017 book Adults in the Room, in which he also recounts a sinister call he received in 2011, before he was a minister but when he was helping journalists investigate banking scandals. The unnamed caller said Varoufakis’s son might not be safe if he continued with his efforts.

Varoufakis recalled his bewilderment at the way the troika conducted its business. “There was fragmentation both horizontal and vertical. There was fragmentation between the institutions. They actually hated each other. The IMF was so critical and dismissive of the Commission – and of the European Central Bank, less so but also – and at the same time the ECB didn’t give a damn about the Commission.

“That was the horizontal fragmentation but there was a vertical fragmentation too. The head of the Commission or the Commissioner for Economic and Financial Affairs would think one thing and his deputy would think something completely different, and you had no idea what to do or who to speak to.

“What was fascinating was that it was the little people, the lower ranks who had more authority, as usual. If you watch Yes Minister you’d know what I mean.”